Various mods over the course of the past three winters
Winter 2017: Cosmetics
Black and red. Black and red was the general theme of the car, but not black and red… enough.
First up was to have the bulkhead powder coated black.
Question: How much of a faff is it to get the bulkhead out. I’d like to get mine powder coated at some point.
Answer: Not to hard to get out, but a few rivets are a pain to reach around the pedals, plus you have to remove the steering rods. I have tapped all the holes to 5mm so I can bolt it back in.
Next up was some red brake and clutch lines and five-point harnesses to continue the theme. Oh, and an increased high level brake light to warn followers.
Winter 2018: More coating
I’ve been convinced that coated exhaust manifolds run cooler — and take less cleaning.
Exhaust and callipers
Given a trip to the coaters was on the cards, it was time for the callipers to have a spruce up too, so off they came. Oh, and while we’re here, I may as well tackle the calliper mounting brackets too.
Somehow, when the coated parts returned, a new fire extinguisher mounting bracket found it’s way to my place (?)
Newly coated exhaust manifold and callipers in place.
Question: Who did you use for the coating?
Answer: I used Performance1coatings (part of the Zirotec group).
And to finish off the winter, a bit of bling in the form of a custom exhaust back box and a new paint job for the nose. Bring on the summer!
Winter 2019: The horses
My car started as a N/A (245bhp) and a couple of years ago had a supercharger added to take it to 310bhp. I’ve never been a fan of the charge cooler side pods and as predominantly a road car, the challenge was to look at the next power hike without adding charge coolers. After much pub chat about the pros and cons of the K20 and K24 engines, the challenge was clear: settle the age-old question of “I wonder what a custom-built K24 block with a K20 head would be like?”.
2.4 engine block, closed deck
Rebore and hone
Head valve guides and seat cuts
Light polish of head ports
Forged pistons to suit new bores
ARP head studs
Uprated valve spring
4 piston uprated oil pump
Upper gasket set
Lower gasket set
Oil pump and chain guides
Modified VTC sprocket
Kit is assembled
Question: Do you need to modify the engine bay to fit that engine in?
Answer: No modification is needed. The gearbox is the same as the original and the engine is only 20mm higher, so will fit OK.
Question: Why did you go the closed deck route? That will surely cause overheating and is unnecessary.
Answer: It provides cylinder strength and adds an element of ‘futureproofing’ for more boost if the mood takes me. Belts and braces.
Engine is ready
Time for the old engine to be replaced and the gearbox to go off for a clean. In the meantime, the new flywheel is now ready too.
Question: what supercharger and inlet manifold are you using? Are you fitting a charge cooler system?
Answer: Standard factory supercharger and inlet manifold
Question: What lightened flywheel did you go for and what is the weight? My current/standard flywheel weighs 4800 grams
Answer: Flywheel weighs in at 4003 grams
Clutch and gearbox is ready
Clutch is a stage 1 unit made by Exedy in Japan — who I am led to believe make the original clutch for Honda. Plus — a shot of the before and after gearbox clean up.
Fuel tank and oil catch tank
Now on to the fluids…the new set up will benefit from an oil catch tank and while everything is stripped down, the fuel tank will benefit from a powder coat.
And everything is in place, with room to spare
Question: Have you changed your fuel pump/injectors?
Answer: No, all standard at present going to get the car on the dyno to see what it does and then change the fuel as required.
Rocker cover challenge
A new rocker cover was required as the catch can pipes would not fit under the cover.
Question: That outlet manifold looks very black. What did you coat that with?
Answer: Outlet manifold was coated by https://www.zircotec.com/
Idler pulley challenge
Ah. Seems the idler pulley is a bit tight to the supercharger. Over to the lathe to make a new one..
Question: Was the idler pulley that close before? Or have you put a larger one on the supercharger to lower boost?
Answer: it’s because the engine block is 19 mm higher than the original 2 litre, so the tensioner’s moved up
Dyno run #1
First run gave 305bhp, which was really disappointing. The reason was the charger wasn’t compressing enough air, so I fitted a larger crank pulley to speed up the charger.
The results are:
Engine 338.1 bhp @ 7855 rpm.
Torque 240.7 lbft @ 6280 rpm.
Boost was (I think) 1.6 bar
Dyno run #2
Another run and tune, this time on a hub dyno.
The car is now pulling 293 HP and 217 lbft at the hub.
The Internet has their various ways of calculating what this means at the wheels on a Rolling Road, but here’s a bit of man maths…
The car left the Dyno #1 Rolling Road at 338 bhp. This was measured as 279 at the hub (a drop of 21%).
Post tune, the hub dyno was reading 293, so with a 21% increase, we are hitting 355 bhp.
Gotta love man maths…
As a road car and not a track car, I am very happy with the results. It needed to be reliable, have room for future upgrades and as I said at the outset – reach 3.5R performance territory without needing charge cooling/side pods. And now we know that a K24 block with a K20 head is a ‘thing’.
Follow the story on the forum
Have a story to tell?